Having the right lawn mowing height is important for a variety of reasons – it reduces stress on the lawn, it prevents the soil from excess run off and evaporation, and it encourages a denser mat which, in turn, reduces the likelihood of pest infestations and disease.
Mowing your lawn at a higher height will create a natural insulating blanket which is able to protect the soil from evaporation. The shorter the lawn the greater the rate of water evaporation. The longer the lawn the lesser the evaporation rate. Leaving the lawn longer will mean less watering is required and when the weather turns warmer a longer lawn will be less likely to dry out, heat up and become damaged.
When lawns are cut too short the lawn itself becomes weaker leaving the plants vulnerable to lawn disease and pest infestations. Shorter lawns also can easily develop bare patches which can allow weeds to take hold. Lawns too short will inherently struggle with the ability to photosynthesise and therefore create food when any stressful conditions such as floods, extreme weather temperatures or drought hits.
With this advice in mind we are not suggesting that you leave your lawn to get too long, but apply the correct lawn mowing height for the lawn variety you have. While each variety has its own recommended mowing height a general standard is between 3-6cms (most people keep them at 1-2cms). Any longer and you can then get issues with the length increasing the speed of growth which just leads to more lawn mowing being required, more lawn scalping and other issues. As an example, for soft leaf Buffalo lawn varieties such as Sir Walter the recommended lawn height is 3.5 – 6.5cms long.
Consider the amount of watering that appears to be required by your lawn, the amount of available sunlight and the weather conditions to help you to determine the height and frequency of mowing best suited to your lawn. If your lawn is thriving with your current practices then continue, if not then it might be best to adjust the mowing height to see if that helps your lawn to cope better.
Overall the best advice is to know the exact recommendation for your lawn variety, never remove more than one third of the leaf at any one time and to balance the height with the season and the needs of both the grass plants and the soil below.